this one i think
Using Vagcom/VCDS open Channel 37 – Navigation, go into adaption and change channel 50 to 1 (will be 0).
To enter the test/setup mode when the RNS 510 is operating press and hold the setup button, keep holding it when the radio menu appears and shortly after the test menu appears . I had to reboot my unit after coding it but it may be possible a power cycle is enough.